Best Time To Fertilize Lawn Before Or After Rain. A soil test is the best way to know whether your lawn needs lime and how much it needs. Do so within 24 hours after fertilizing.
Consider doing it within the first 24 hours of the application. The best time to fertilize your lawn is in the afternoon or evening when the sun is not burning high in the sky anymore. To absorb all the nutrients of your fertilizer at the root level, you need to turn on the irrigation for that 20 minutes.